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a)    are used after an independent clause to introduce a list.
       e.g.  Complete sentence: additional information.

       correct:  I like fruit: apples, oranges, and plums. 
       incorrect:  I like fruit such as: apples, oranges, and plums.
b)    are used for explanations.
       e.g. Complete sentence: Complete sentence.

       The guy is amazing: He has canoed all of the Great Lakes.


a) set off supplementary information.

Brown discusses his passions—camping and hiking—in detail.


a) indicate omission of text within a quoted sentence. When leaving text out within a sentence, use only 3 spaced dots.

"They discovered…excellent advertisement techniques" (Borden, 2001, p. 28).

b) when leaving out a piece of text that is followed by a new sentence, use 3 dots to indicate the ellipses and 1 dot to indicate the period.

"Ancient astronomers believed that the Earth was the center of the universe . . . Copernicus proved that Earth and the other planets in our solar system orbit our sun" (NASA, 2012, para. 8).


a) join related independent clauses in compound sentences.
       e.g.  Complete sentence; complete sentence.

The day was cloudy; I could not see the sun.
b) separate items in a series if the items already include commas.

Members of the committee included Dr. Andrew Smith, director; Dr. Harriet Clemens, cardiologist; and Charlotte Jackson, registered nurse.

Square Brackets

a) enclose words or comments you have inserted into a quotation.

Yu (2009) states, "[doctors] need to continue their development in the field" (p. 45).

b) enclose the word sic to indicate a word has been quoted exactly as in the original text even though it may contain spelling or other mistakes.

He worked hard to "identefy [sic] the problem" (Cha, 1999, p. 6).


a) separate three or more items in a list.

Snacks, stamps, and clothing can be purchased at Conestoga's Bookstore.
b) set off introductory...

  • words: Therefore, I will book an appointment with the Writing Centre.
  • phrases: At Student Life, students can find exciting ways to get involved.
  • clauses: If students want to improve their skills, they can come to our school.

c) surround words that are not essential for the meaning of the sentence.

Databases, such as CINAHL and EBSCOhost, provide access to journal articles.
d) precede a direct quotation.

The student stated, "The extra help is a big part of why I do so well in school."

e)   accompany "FANBOYS" (for, and, nor, but, or, yet, so) to connect 2 independent clauses.

I want to go camping, but it is going to rain this weekend.

Use a comma before "and" …

a) when there are 3 or more items in a list.

She likes to play baseball, soccer, and hockey.
b) when it connects 2 independent clauses (2 sentences).

He wrote the final exam, and he finished his last assignment.

Note: DON'T use a comma before "and" between just 2 items.


She's finished her essay and her assignment.